linux-imx

/*

 * Copyright (C) 2012 Red Hat, Inc.

 *

 * This file is released under the GPL.

 */

​

#include "dm-cache-metadata.h"

​

#include "persistent-data/dm-array.h"

#include "persistent-data/dm-bitset.h"

#include "persistent-data/dm-space-map.h"

#include "persistent-data/dm-space-map-disk.h"

#include "persistent-data/dm-transaction-manager.h"

​

#include <linux/device-mapper.h>

#include <linux/refcount.h>

​

/*----------------------------------------------------------------*/

​

#define DM_MSG_PREFIX   "cache metadata"

​

#define CACHE_SUPERBLOCK_MAGIC 06142003

#define CACHE_SUPERBLOCK_LOCATION 0

​

/*

 * defines a range of metadata versions that this module can handle.

 */

#define MIN_CACHE_VERSION 1

#define MAX_CACHE_VERSION 2

​

/*

 *  3 for btree insert +

 *  2 for btree lookup used within space map

 */

#define CACHE_MAX_CONCURRENT_LOCKS 5

#define SPACE_MAP_ROOT_SIZE 128

​

enum superblock_flag_bits {

    /* for spotting crashes that would invalidate the dirty bitset */

    CLEAN_SHUTDOWN,

    /* metadata must be checked using the tools */

    NEEDS_CHECK,

};

​

/*

 * Each mapping from cache block -> origin block carries a set of flags.

 */

enum mapping_bits {

    /*

     * A valid mapping.  Because we're using an array we clear this

     * flag for an non existant mapping.

     */

    M_VALID = 1,

​

    /*

     * The data on the cache is different from that on the origin.

     * This flag is only used by metadata format 1.

     */

    M_DIRTY = 2

};

​

struct cache_disk_superblock {

    __le32 csum;

    __le32 flags;

    __le64 blocknr;

​

    __u8 uuid[16];

    __le64 magic;

    __le32 version;

​

    __u8 policy_name[CACHE_POLICY_NAME_SIZE];

    __le32 policy_hint_size;

​

    __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];

    __le64 mapping_root;

    __le64 hint_root;

​

    __le64 discard_root;

    __le64 discard_block_size;

    __le64 discard_nr_blocks;

​

    __le32 data_block_size;

    __le32 metadata_block_size;

    __le32 cache_blocks;

​

    __le32 compat_flags;

    __le32 compat_ro_flags;

    __le32 incompat_flags;

​

    __le32 read_hits;

    __le32 read_misses;

    __le32 write_hits;